/*
 jChecs: a Java chess game sample 

 Copyright (C) 2006-2011 by David Cotton

 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
 Foundation; either version 2 of the License, or (at your option) any later
 version.

 This program is distributed in the hope that it will be useful, but WITHOUT
 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with
 this program; if not, write to the Free Software Foundation, Inc., 51 Franklin
 Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */
package fr.free.jchecs.ai;

import java.io.Serializable;
import java.util.Comparator;

import fr.free.jchecs.core.Move;
import fr.free.jchecs.core.Piece;

/**
 * Propose un tri statique des mouvements, classant les mouvements avec prise
 * devant les mouvements sans prise. Les mouvements avec prise sont classés de
 * la prise la plus forte à la pris la plus faible.
 * 
 * @author David Cotton
 */
final class StaticMoveSorter implements Comparator<Move>, Serializable {
	/** Identifiant de la classe pour la sérialisation. */
	private static final long serialVersionUID = -1345309675511434759L;

	/**
	 * Crée une nouvelle instance.
	 */
	StaticMoveSorter() {
		// Rien de spécifique...
	}

	/**
	 * Tri des mouvements.
	 * 
	 * @param pMvt1
	 *            Premier mouvement.
	 * @param pMvt2
	 *            Deuxième mouvement.
	 * @return -1, 0, 1 en accord avec le contrat de compare().
	 * @see Comparator#compare(Object, Object)
	 */
	@Override
	public int compare(final Move pMvt1, final Move pMvt2) {
		final Piece prise1 = pMvt1.getCaptured();
		final Piece prise2 = pMvt2.getCaptured();
		if (prise1 == null) {
			if (prise2 != null) {
				return 1;
			}
		} else {
			if ((prise2 == null)
					|| (prise1.getType().getValue() > prise2.getType()
							.getValue())) {
				return -1;
			}
		}

		final int val1 = pMvt1.getPiece().getType().getValue();
		final int val2 = pMvt2.getPiece().getType().getValue();
		int res = 0;
		if (val1 > val2) {
			res = -1;
		} else if (val1 < val2) {
			res = 1;
		}
		if ((prise1 != null) && (prise2 != null)) {
			res = -res;
		}

		return res;
	}
}
